*{box-sizing:border-box;margin:0;padding:0;font-family:Arial,sans-serif}body{color:#fff;background:#111;overflow:hidden}#layout{grid-template-columns:420px 1fr;height:100vh;display:grid}#sidebar{background:#181818;border-right:1px solid #333;padding:24px;overflow-y:auto}.card{flex-direction:column;gap:12px;display:flex}input{color:#fff;background:#222;border:none;border-radius:12px;padding:12px}button{color:#000;cursor:pointer;background:#fff;border:none;border-radius:16px;padding:16px;font-weight:700}#viewer{width:100%;height:100%}